How to heat up a bullet gun faster? Shot and accompanying factors Damaging factors of a shot.
The topic of liquid propellant mixtures is one of those topics that appears and then disappears again. Discussions about the possibility of using some kind of explosive liquid instead of gunpowder in cartridges and shells often proved fruitless. It quickly came to the conclusion that “nothing is impossible” and the discussion ended there.
It would seem, what else can be added to this topic? It turns out that it is possible, and quite a lot. The list of substances and their mixtures suitable as a liquid propellant is quite large and there are very interesting options. But now we will focus on one long time ago known substance- hydrogen peroxide.
Hydrogen peroxide is a transparent substance that looks like water. The photo shows 30% peroxide, better known as perhydrol.
Hydrogen peroxide has been widely used and is currently used in rocketry. The famous Aggregat 4, better known as V2, used hydrogen peroxide to drive turbopumps that pumped fuel and oxidizer into the combustion chamber. Hydrogen peroxide is used in the same capacity in many modern rockets. The same substance is also used for mortar launch of missiles, including in underwater launch systems. Also, the German Me-163 jet aircraft used concentrated hydrogen peroxide (T-Stoff) as an oxidizing agent.
Chemists were well aware of the ability of hydrogen peroxide, especially in high concentrations, to decompose instantly, with an explosion and the release of large amounts of water vapor and oxygen heated to high temperatures (the decomposition reaction occurs with the release of heat). 80% hydrogen peroxide produced a vapor-gas mixture with a temperature of about 500 degrees. A liter of such hydrogen peroxide upon decomposition gives, according to various sources, from 5000 to 7000 liters of steam gas. For comparison, a kilogram of gunpowder produces 970 liters of gases.
Such properties fully allow hydrogen peroxide to act as a liquid propellant. If the steam gas from the decomposition of hydrogen peroxide is capable of rotating turbines and pushing out ballistic missiles from the launch shaft, then he is even more capable of pushing a bullet or shell out of the barrel. This would provide major benefits. For example, the possibility of significant miniaturization of the cartridge. However, as is well known to any person knowledgeable in firearms, hydrogen peroxide has never been used or even proposed as a propellant. There were reasons for this, of course.
Firstly, hydrogen peroxide, especially concentrated, instantly decomposes explosively upon contact with most metals: iron, copper, lead, zinc, nickel, chromium, manganese. Therefore, any contact with the bullet or cartridge case is impossible. For example, trying to pour hydrogen peroxide into a cartridge case would lead to an explosion. Safe storage of hydrogen peroxide during the birth and most rapid development of cartridge technology was possible only in glass vessels, which posed insurmountable technological barriers.
Secondly, hydrogen peroxide, even in the absence of catalysts, slowly decomposes, turning into water. average speed The decomposition of the substance is about 1% per month, so the shelf life of hermetically sealed hydrogen peroxide solutions does not exceed two years. It was not very convenient for ammunition; they could not be produced and stored for decades, like conventional cartridges.
The use of a new propellant such as hydrogen peroxide would require such major changes in production, storage and use firearms and ammunition for it, that they did not even dare to carry out such experiments.
However, why not try? Several very compelling arguments can be made in favor of hydrogen peroxide, albeit of a somewhat unusual nature, mostly military-economic. If the arguments are best considered together with the proposed design of a cartridge with a charge of hydrogen peroxide, so as not to repeat it twice.
First. Hydrogen peroxide (and some mixtures based on it) is a propellant, produced completely without the participation of nitric acid, this indispensable reagent for the production of all types of gunpowder and explosives used. In the military economy, mastering the production of at least part of the propellant or explosives without the use of nitric acid means the possibility of increasing the production of ammunition. In addition, as the experience of the same Germany during the Second World War shows, all nitric acid and all ammonium nitrate (in Germany it was used both as an explosive and as a component of artillery gunpowder) cannot be used only for ammunition. Something else needs to be left for Agriculture, because bread is no less important for war than gunpowder and explosives.
And the production of nitrogen compounds is a huge plant, vulnerable to aviation or missile strike. In the photo - Togliattiazot, Russia's largest ammonia producer.
Hydrogen peroxide is produced mainly by electrolysis of concentrated sulfuric acid, and subsequent dissolution of the resulting persulfuric acid in water. From the resulting mixture of sulfuric acid and hydrogen peroxide, 30% hydrogen peroxide (perhydrol) can be obtained by distillation, which can be purified from water using diethyl ether. Sulfuric acid, water and ethyl alcohol (which is used for the production of ether) are all the components for the production of hydrogen peroxide. Organizing the production of these components is much simpler than the production of nitric acid or ammonium nitrate.
Here is an example of a hydrogen peroxide production plant from the Solvay company with a capacity of up to 15 thousand tons per year. A relatively compact installation that can be hidden in a bunker or some other underground shelter.
Concentrated hydrogen peroxide is quite dangerous, but rocket scientists have long developed a mixture that is explosion-proof under normal conditions, consisting of a 50% aqueous solution of hydrogen peroxide with the addition of 8% ethyl alcohol. It decomposes only with the addition of a catalyst, and gives steam gas more high temperature- up to 800 degrees, with appropriate pressure.
Second. Apparently, loading a cartridge with hydrogen peroxide will require much less than gunpowder. It can be assumed for rough calculations that this substance produces on average 4 times more gases than gunpowder, that is, to obtain the same volume of gases, the volume of hydrogen peroxide is required to be only 25% of the volume of gunpowder. This is a very conservative estimate, since I could not find more accurate data, and the data available in the literature vary greatly. It is better not to get carried away with more accurate calculations and tests.
Let's take the 9x19 Luger cartridge. The internal volume of the cartridge case occupied by gunpowder is 0.57 cubic meters. cm (calculated from geometric dimensions).
Geometric dimensions of the 9x19 Luger cartridge.
25% of this volume will be 0.14 cubic meters. cm. If we shortened the cartridge case to such a volume occupied by the propellant, then the length of the cartridge case would be reduced from 19.1 to 12.6 mm, and the length of the entire cartridge would be reduced from 29.7 to 22.8 mm.
But here it should be noted that with a cartridge diameter of 9 mm, the volume for the propellant charge is 0.14 cubic meters. cm requires a height of only 2.1 mm. And the question arises: do we even need a sleeve here? The bullet length in this cartridge is 15.5 mm. If the bullet is increased in length by 3-4 mm, make it with back side cavity for the propellant charge, then you can discard the cartridge case as such. The ballistic characteristics of the bullet will, of course, change, but it’s unlikely to change dramatically.
This scheme is not suitable for a powder charge: the bullet-case is quite long and has mediocre ballistic characteristics. But if the propellant charge turns out to be only a fifth of the powder charge, then such a cartridge in the form of a bullet-case turns out to be quite possible.
There is no need to say how important it is to reduce the weight of ammunition and reduce its size. Such a radical reduction in the size of the same pistol cartridge that it shrinks, in fact, to the size of a slightly enlarged bullet, creates great prospects for the development of weapons. Reducing the size and weight of the cartridge by almost half means the possibility of increasing the magazine. For example, the PP 2000, instead of magazines for 20 and 44 rounds, can receive magazines for 40 and 80 rounds. The same can be said not only about the 9x19 cartridge, but also about all other cartridges for small arms.
You can also remember about the VAG-73 V.A. pistol. Gerasimov for caseless cartridges.
Third. Modern containers for storing hydrogen peroxide and mixtures based on it are made of polymers: polystyrene, polyethylene, polyvinyl chloride. These materials not only provide safe storage, but also make it possible to create a capsule for loading ammunition that is inserted into the cavity of the bullet. The capsule is sealed, equipped with a capsule. The capsule in this case is a relative concept. Hydrogen peroxide does not need to be set on fire, like gunpowder, but rather it needs to be added very lightly. a large number of catalyst. Essentially, the “primer” in this case is a small nest in a plastic capsule containing the propellant, where the catalyst is placed. The strike of the striker pierces this socket, its bottom, separating it from the propellant, and presses the catalyst inside the capsule. Next, the decomposition of hydrogen peroxide occurs, the rapid release of steam gas and a shot.
The capsule is best made from polystyrene. It is quite durable under normal conditions, but when heated strongly, above 300 degrees, it decomposes into the monomer - styrene, which, in turn, when mixed with oxygen present in the steam gas, burns well and even explodes. So the capsule will simply disappear the moment it is fired.
A cartridge with hydrogen peroxide in a section. 1 - bullet. 2 - hydrogen peroxide. 3 - polystyrene capsule. 4 - “capsule” with a decomposition catalyst.
A polystyrene capsule is produced incomparably lighter and simpler than a sleeve. It is easy to stamp hundreds and thousands of pieces on a heat press in one pass. Numerous (more than a hundred!) operations for the manufacture of a metal cartridge case are completely eliminated, and the technological equipment for producing a shot is dramatically simplified. The relative simplicity of production means the possibility of mass production and its expansion if necessary.
However, it should be noted that cartridges filled with hydrogen peroxide will need to be manufactured immediately before use, with a maximum shelf life of 3-4 months. The longer such a cartridge is in storage, the more difficult it is to guarantee that it will work. But this circumstance can be circumvented in the following simple way: equip with fresh hydrogen peroxide or a mixture based on it only those batches of cartridges that will immediately go into use. It will be necessary to change the very sequence of ammunition manufacturing. If in conventional cartridge production the cartridge is loaded with gunpowder before mounting the bullet, then in the case of hydrogen peroxide the final stage of ammunition production will consist of pouring it into the already assembled ammunition. Hydrogen peroxide can be poured into the capsule already installed in the bullet using a thin needle (aluminum or stainless steel - materials acceptable for working with this substance), followed by sealing the hole.
Because in Peaceful time it is possible to prepare a sufficient mobilization supply of “dry” cartridges in order to quickly launch the production of fresh hydrogen peroxide and accelerate the equipment of these supplies in case of war.
However, some of these cartridges can be kept in warehouses and fully loaded. After the expiration date, the hydrogen peroxide in them can be replaced without disassembling the ammunition: using a thin needle, first pump out the already unusable propellant mixture, and then pour in a fresh one.
In general, if you decide to make major changes related to the design of the cartridge, the design of the weapon, as well as the technology of cartridge production, then you can introduce a new propellant and obtain a whole range of military, economic and tactical advantages associated with its use. These advantages, as can be seen, will be very far-reaching and will affect all aspects of preparation for war.
The very idea of this method of charging a cartridge appeared back in the days
First World War.
When German soldiers When they saw that their rifles could not penetrate the armor of British Mark I tanks, they decided to try loading the bullets with the point inside the cartridge case.
And to their surprise, the bullets began to dent the armor. Because of this, the armor crumbled inside the tank and maimed the crew. But then the soldiers discovered that firing such cartridges often disabled rifles and injured the shooters themselves, and this method of loading cartridges was abandoned.
Then the Germans adopted armor-piercing bullets, and British tanks became vulnerable again.
Bullets Loaded Backwards
The video tested the killing power of a bullet charged in this way. When hitting the ballistic gel, the bullet does more damage than a standard bullet.
Neither bullet nor the other penetrated sheet steel. But it completely tore the water bottle, unlike the traditional one, which simply pierced it right through.
But there was also a downside to such cartridges, namely a cracked cartridge case. So, if you care about your safety, it is better not to repeat this.
What happens if you weld cartridges?
The unscientific experiment, conducted by the magazine Master-Ruzhye, was carried out in laboratory conditions (an armored room) with constant visual monitoring of the cooking process. We strongly recommend that you dear readers, believe in the results of these tests and do not try to repeat them in practice: in the kitchen, on garden plot and so on. The illustrations for the article, except for the target, are, of course, staged shots. We are giving this warning for a reason. After the article was published. Rail War. non-believers were found who repeated that experiment in the field. conditions and joyfully reported this to the editor: .And it’s true, it didn’t hit, but the ricochet whistled right over my head!..
I’ll paraphrase Said from White Sun of the Desert: DON’T DO THIS, DON’T!
In a wonderful domestic film. Roadblock. There is a moment when fighters cook machine gun cartridges with the aim of later using them as hard currency in business. relationships with.fairies.. From various independent sources, I also received information about this and other methods.of finishing. ammunition before handing it over to a potential enemy. Moreover, the subtlety of such modernization is not to make the cartridge unsuitable for shooting, on the contrary, the entire outer side of the shot. the sound, sensations, and operation of the reloading mechanism should remain without visible changes. But the ballistics of the modified cartridges should exclude the possibility of their combat use at any significant distances.
Not that I have any doubts about the existence of such a practice at all or about the effectiveness of the techniques used. Rather, on the contrary, remembering that practice. criterion of truth, I decided to establish the exact time and operating parameters for processing cartridges to bring them to the desired (in certain cases) state.
It must be said that popular rumor offers several more culinary options. recipes that give (presumably) similar results to the cinematic version. Let's consider several proposed methods, the effectiveness of which we will have to confirm (refute) during experiments.
7.62x39 cartridges are cooked for a certain amount of time, after which they lose their combat properties.
It is not necessary to cook the cartridges for a long time; the main thing is to quickly cool the very hot cartridge.
It takes a long time to cook, but it takes a long time to cool. slowly, allowing the cartridges to cool quietly in the water where they were boiled.
A little theory
From a physical point of view, for a noticeable change in the ballistics of a bullet, you just need to reduce its initial speed by about 300 meters per second. At a distance of 100 m, this will lead to such a decrease in the trajectory that, with normal aiming, it will be problematic to hit a chest target, and at 200 m, a height target. What factors can lead to such success?
Assumptions
Partial decomposition of the primer composition, weakening of the force of the primer flame and, as a consequence, . incomplete combustion of the powder charge (often observed in hunting cartridges when using old centrifugal capsules).
Wetting of the primer composition and the powder charge due to water seeping into the cartridge.
Partial thermal decomposition of a powder charge.
In my opinion, of the three versions, only the third deserves serious attention. The first assumption is unfounded, since the thermal stability of initiating substances significantly exceeds the potential of culinary substances. capabilities of an ordinary person. The second assumption is very plausible. However, getting the powder charge wet will lead to the complete loss of the cartridge's combat properties, and this. not our option. So, the third version. It must be said that the low chemical and thermal resistance of nitrocellulose, which forms the basis of most smokeless powders, was a big problem for chemists and the military at the end of the 19th century. And the point was not only that it was not possible to completely purify nitrocellulose from the remnants of the acid mixture used for nitration.
Slow, spontaneous decomposition of nitrocellulose molecules occurred with the release of the nitric acid radical NO2,. as a consequence, the acidity of the environment increased, and the rate of decomposition process increased many times over. Played a decisive role temperature regime. With an increase in temperature by 10., the speed of the process doubled. Thus, the rate of self-decomposition of gunpowder with an increase in temperature from 0. to 100. C increased by 1024 (!) times. Later, special substances (for example, diphenylamine) began to be introduced into the composition of gunpowder, the function of which was to bind excess acid that inevitably formed during long-term storage of gunpowder. The durability of gunpowder has increased significantly. Under normal storage conditions, cartridges and shells remained suitable for firing for decades. However, boiling for several hours cannot be recognized normal condition storage, so it was with this path that I pinned the greatest hopes when starting experiments.
From words to deeds
For the easiest test, I soaked a pack of Klimov FMJ cartridges in a nickel-plated case in water for one week.
Some of the cartridges (made in Barnaul) with the SP bullet were boiled for one hour.
Some of the cartridges from the same batch. in two hours.
According to unverified information, 30 minutes of boiling is enough to disable a 9 mm PM cartridge, so with an automatic cartridge I decided to stop at the 2-hour mark.
I’ll say right away that when I went to the shooting range, I prepared for the worst. The effect of the treatment was difficult to predict, and the prospect of a bullet getting stuck in the barrel seemed very likely to me. One of my acquaintances told me with sympathy that in the army stuck bullets were removed using a special rod (a regular ramrod was bent), a concrete wall, etc. An armored personnel carrier that pressed on the rod. In my army practice, there were no such cases, and I also did not specify why the bullets got stuck in the machine gun barrels, but I went to the firing line with a restless soul.
The target was placed at the 50th mark, and I didn’t particularly hope to hit it. Shot!.. Another one and another. All 10 shots went through without delay, forming a completely normal group of about 60 mm on the target. Having fired, I hurried to the speed measuring device, secretly hoping to see the expected 600 m/s. Nothing happened. The speeds were about 700-715 m/s at a distance of 20 m from the muzzle. Uncooked cartridges from the same batch gave approximately the same speed.
It was the turn of the two-hour game. And again, not a single delay. The chronograph showed a minimum speed of 697, a maximum. 711. And no downward trend. Frankly, this was a real disappointment. Klimov cartridges, soaked for a week, worked depressingly monotonously (708-717 m/s). .Soviet power is strong., . I thought and decided to increase the cooking time to 3 hours. It's been said. made. A week later I arrived at the shooting range with four loads of ammunition.
Barnaul. S.P. 3 hours.
.Klimovsk. HP (without varnish filling). 3 hours.
.Barnaul. FMJ. 3 hours with rapid cooling in the freezer.
The same, but with a smooth cooling in the original. water.
The very first speed measurement really shocked me. The chronograph showed 734, 737, 736, 739. .This cannot be., . I thought. The misunderstanding was cleared up very quickly. the device stood three meters from the trunk, and not twenty. like before. The deceleration speed of a bullet is about 1 m/s for every meter of distance. Thus, at 20 meters the device would show the same 710-715 m/s as last time. The control group cartridges at 3 m showed 735 m/s. Only one shot from boiled cartridges gave 636 m/s. The cartridges of the second group misfired twice per 10 shots. In the absence of varnish filling of the cartridge case neck and primer, water managed to get inside, which was confirmed later when I sawed the misfire cartridge. The gunpowder was thoroughly wet and did not even fall out. In refutation folk recipes, cartridges of the 3rd and 4th groups worked exactly the same as the others. The idea of the article collapsed before our eyes. Angry at the failure, the pouring rain in which the shooting was carried out, the cinematography and everything in general, I decided to take the last step and cook the cartridges for 5 hours.
In general, setting up experiments of this kind. It's a pretty routine thing. The main concern of the experimenter. do not allow the water to completely boil away. After 5 hours of boiling, half of the cartridges were immediately removed from the water, and I let the second one cool slowly right in the broth. Frankly, I did not see a fundamental difference between the methods; the only reasonable explanation was the following: if the gunpowder really decomposed under the influence of high temperature, then the resulting gases had to be released through damage to the varnish fill. As it cooled, a vacuum should have been created inside the cartridge, and water should have been sucked in through the same damage to the filling. The truth of this assumption was to be determined at the shooting range.
The practical result of firing 7.62x39 RMZ cartridges after a five-hour boil: seven hand-held shots at a distance of 25 meters.
I’ll tell you straight, when I went to the firing line, my secret sympathies were already on the side of the Barnaul machine tool builders, and not the recipes of folk cooking, as before. First, the first batch of cartridges (Barnaul FMJ) were tested. The chronograph stood five meters away. The target hung at twenty-five. The very first shots showed the unconditional superiority of the machine production method over the pitiful efforts of a single artisan. The chronograph was relentless. 738, 742, 746, 747, 749, 751, 759 (!). The bullets lay flat. One break. entirely my fault. The speed values even seemed a little high to me. The question is whether the increase in initial velocities was the result culinary processing or a feature of a given batch of cartridges, remained open. The cartridges of the second batch (those that cooled in water) also did not cause any misfires or malfunctions in the automation. Accuracy was normal, however, measuring the speeds of 10 shots in three cases resulted in a decrease in speed to 673, 669, 660 m/s.
At this point I decided to stop conducting experiments. No, no, dear reader, it’s not that my research enthusiasm has dried up. The speed reduction values obtained as a result of the experiments were still infinitely far from the desired 400 m/s. And here appearance cartridges after 5 hours of cooking are more than three. obviously didn't pull it off. Rough to the touch, covered with a whitish coating of scale, with a noticeably peeling varnish coating of the cartridge case, with the varnish filling of the cartridge case swollen like a soggy bread crust, they have clearly lost their presentation. You didn't have to be an expert to understand that there was something wrong with the cartridges.
Instead of a conclusion
It is possible that the statistics I collected are not sufficient to make broad generalizations. Possibly soldiers of the checkpoint. They cooked the cartridges not for five hours, but for five days, taking turns watching the pot. Perhaps you should cook not in water, but in some higher boiling liquid, for example, oil. One way or another, in my case, domestically produced cartridges showed the highest resistance to all kinds of force majeure circumstances. I can only console myself with the fact that I remember the ax in the old soldier’s tale. also remained undercooked.
Soldiers and sailors, sergeants and petty officers, officers of all branches of the military, love Russian cinema, but remember that the truth of art may not always coincide with the truth of life!
pcmist 02/23/2016 - 20:39
The bottom line is that in order for the bullet to reach operating temperature, so that the bullets are produced without sagging and have the same mass, you need to make 20-30 bullets per rejection, in the case of complex shapes like paradox, a bullet only at 5 or even 6 degrees is ideal.
Does anyone have ways to quickly or autonomously heat bullets? So that the bullet gun itself would heat up, I took it and started making “finish” bullets from the very first casting.
Maybe preheat it in the oven or something?
pcmist 02/23/2016 - 21:00
By the way, yes, I’ll try the electric stove!
Onuris 02.23.2016 - 22:15
I use a spiral electric burner from a 1 kW “Dream” stove, for faster heating, I additionally use a gas burner that runs on gas cartridges. The bullet for the Diabolo and Koratkov bullet, after pouring the lead, has to be thrown into the water, otherwise the bullet is very difficult to get out, but on the burner and with gas, it heats up in 20-30 seconds, and the new bullet comes out perfect. A gas cylinder is enough for 80-100 bullets.
pcmist 02/23/2016 - 23:03
I have a Lee crucible
Bloodsucker 02/23/2016 - 23:22
Well, this is an ass... overheat the lead... but how?
pcmist 02/24/2016 - 12:38
What are the signs of lead overheating and what does it mean?
Evgeny_k26 02/24/2016 - 08:17
What if you don't pull out the bullet right away? In theory, it should give its heat to the watering can. I do like this. I hold the first five to ten bullets longer until it turns out without defects
pcmist 02/24/2016 - 08:45
Evgeny_k26
What if you don't pull out the bullet right away? In theory, it should give its heat to the watering can. I do like this. I hold the first five to ten bullets longer until it turns out without defects
Well, this is understandable, but personally, for absolutely perfect bullets, so that I wouldn’t be ashamed to sell to people, I have to make much more test castings. Especially bullets with a complex profile, such as a paradox. I pour on the balcony, it’s about zero or a small minus. Maybe this has an effect.
Mikha78 02/24/2016 - 09:03
I have lead in the crucible, and the watering can is on a piece of iron 5 mm thick, which in turn is on a gas stove, which is powered by spray cans. I turn them on at the same time. When a frost pattern appears on bullets, this is the first sign of overheating.
CodeF 02/24/2016 - 09:09
pcmistHave you seen what they sell in stores? 😀. Bullet quality.
so that people aren’t ashamed to sell bvlo
pcmistI'm heating it over the crucible. The bullet is placed so that it almost touches the lead. And it stays there for a while. The main thing is not to overheat, otherwise if the handles are wood, they might get charred 😊.
By the way, I tried to heat it on a tile - this scheme does not work (((
Overheated lead - the bullets will be brittle. I recently became convinced of this myself.
Bloodsucker 02/24/2016 - 11:28
I heat it in a cast iron stove on a gasoline burner.
After complete melting, I let it sit on the fire for another five minutes, after which I start pouring it into the extra watering can. The first five bullets go back into the cast iron, after which they are working.
PRINCIP 02/24/2016 - 12:05
pcmistTry smoking the working surfaces of the watering can.
or something else?
A thin layer of soot will reduce the rate of heat transfer from the lead to the mold.
For example, Viktor Polev covers his molds (made of steel) with a layer of iron oxide.
That is, the heated form is coated with a supersaturated solution of iron sulfate... the surface is covered with a thin layer of rust.
AzSs 02/24/2016 - 15:40
I heat it with lead, send the first 10 bullets back to the smelter and that’s it.
Sometimes I just put a watering can on the lid of the crucible while it heats the lead.
------------------
It’s better to be shocked by what you hear than to be shocked by what’s happening.
Ivanov 02.24.2016 - 18:35
Good day.
When the ambient air temperature is low, it takes a very long time to reach the mode, and it only flows when the bullet is pressed closely to the crucible nozzle. I moved to the bathroom for the winter.
Sincerely, Alexander.
A shot is the process of ejecting the energy of powder gases formed as a result of the combustion of gunpowder from a burning charge, its incompletely burned or unburned parts, a projectile and pre-bullet air from the barrel bore.
When firing a firearm loaded with a cartridge, after pressing the trigger the striker strikes the primer, causing the primer composition and the powder charge to ignite. The combustion of gunpowder produces a large amount of gases that seek a way out, pressing on the bullet, the walls of the barrel bore, and the bottom of the cartridge case. The least strongly reinforced bullet, under gas pressure, begins its movement along the barrel, which always contains air. Some gases break through between the bullet and the wall of the bore, but in the bore they always follow the pre-bullet air.
Immediately after the explosion of the primer composition, the first shock wave is formed, reaching the speed of sound in the barrel bore. Coming out of the barrel, it takes on a spherical shape, accompanied by a flash and an explosion or the sound of a shot (sound wave). It is followed by part of the powder gases, ahead of the bullet. The second shock wave separating from them catches up with the sound wave, and they follow together. After the bullet leaves the barrel, the bulk of the powder gases escape, which “push” the previously formed gas cloud. Moving initially at a speed exceeding the initial speed of the bullet, the powder gases outstrip it and form a third shock wave. Combining, all the waves form a single elliptical shock wave with a bullet flying behind it, and then, due to the loss of speed from air resistance, the bullet catches up with the shock wave and gets ahead of it. The distance at which the bullet is ahead of the shock wave is different for different types of weapons.
When exiting the barrel, depending on the distance of the shot, the first to act when firing at point-blank range is the pre-bullet air, at close range - gases, at close range - the bullet.
The morphological features of gunshot injuries are determined by the influence of the damaging factors of the shot.
Damaging factors of a shot
The damaging factors of a shot include factors that arise as a result of a shot and have the ability to cause damage. Pre-bullet air, combustion products of gunpowder and capsule composition (powder gases, soot, particles of powder grains, tiny metal particles) have the ability to cause damage; weapons and their parts (barrel muzzle, moving parts (bolt), butt (during recoil), individual parts and fragments of a weapon that exploded at the moment of firing); firearm projectile (bullet - whole, deformed or fragmented; shot or buckshot, atypical projectiles of homemade weapons); secondary projectiles - fragments and fragments of objects and obstacles damaged by the projectile before hitting the body, fragments of damaged bones during the passage of a bullet in the human body (Diagram 19).
The nature of the damaging factors of a shot depends on the characteristics of the weapon and cartridge, the size of the powder charge, the caliber of the bore and the length of the barrel, the distance of the shot, the presence of an obstacle between the weapon and the body, and the anatomical structure of the affected area.
Pre-bullet air
A bullet moving at high speed compresses and throws air out in front of itself with great force, giving it a translational and rotational motion created by the rifling of the barrel bore.
The air jet, depending on the distance of the shot and the size of the charge, can cause either superficial skin abrasions, a ring of “air abrasions”, or minor bruises in the subcutaneous tissue or thickness of the skin, or extensive skin tears. Precipitation may be invisible immediately after the shot and appear after 12-20 hours. Pre-bullet air and part of the powder gases that advance the bullet tear clothing and even skin. The bullet that entered after them does not contact the tissue and does not form a tissue defect, and therefore it is sometimes not detected by bringing the edges of the damage together, which should be remembered when determining the entrance hole and the distance of the shot when inspecting the scene of the incident.
Powder gases
Gases are formed during the combustion of gunpowder, resulting in high pressure and an explosion that ejects the projectile from the cartridge case and bore.
Powder gases exert pressure not only on the projectile, but also on the walls of the cartridge case, the barrel bore, and also through the bottom of the cartridge case to the bolt.
IN automatic weapons Gas energy is used for recharging.
The pressure of the gases causes recoil, which, if the weapon is not held correctly, causes damage and occasionally ruptures of the barrels, usually from shots from homemade weapons. Gases escape after the bullet. Some of them break through between the bullet and the bore, the rest follow the bullet, overtaking it at the exit from the bore of the weapon. Coming out of the barrel, the gases flare up and the sound of a shot is heard. The gases escaping from the barrel have high pressure (1000-2800 kgf/cm2), high temperature and speed. A 9 mm bullet from a Makarov pistol, leaving the barrel, has an initial speed of 315 m/s, a 7.62 mm bullet from a Kalashnikov AKM assault rifle has an initial speed of 715 m/s.
Powder gases carry with them part of the burnt primer composition, solid combustion products of gunpowder, incompletely burned powder particles, metal particles torn from the primer, cartridge case, projectile, and bore. Depending on the type of gunpowder and the distance of the shot, the gases have a mechanical (piercing, explosive, bruising), chemical and thermal effect.
Mechanical action of gasesdepends on the pressure in the barrel bore, which reaches hundreds and thousands of atmospheres, the distance of the shot, the anatomical area of the body, the structure of tissues and organs, the quality of ammunition, and the thickness of tissues.
The higher the pressure and the shorter the distance, the greater the destruction.
Entering the body, gases exfoliate tissues with loose fiber, tear tissues from the inside, and exfoliate the skin in the direction of elastic fibers.
If the affected object in the affected area is small in thickness, then the effect of the mechanical action of gases can also appear in the area of the outlet on the hands and feet. In these cases, clothing may also tear.
Powder gases have a significant impact on the shape and size of entrance and exit wounds, which are determined by strength, elasticity, degree of tension, friability, location of the underlying tissues of the injured area of the body, the type of weapon and cartridge.
The mechanical effect of powder gases is manifested in cases of a shot at an unsealed stop, when they lift the skin from the inside, press it, hit it against the front end of the weapon, which seems to plunge into the wound and form a stamp mark called S.D. Kustanovich (1956) with an imprint of the muzzle end of a weapon. The piercing effect of gases manifests itself during a shot into a sealed stop, explosive - into an unsealed one, and bruising - from a short distance.
Chemical action of gases . When gunpowder burns, it releases a significant amount of carbon monoxide. If the latter combines with hemoglobin in the blood, carboxyhemoglobin is formed, which has a light red color. This feature was first pointed out by Shlokov (1877), and its presence in the area of the inlet was proven by Paltauf (1890).
M.I. Avdeev drew attention to the presence of such staining in the area of the outlet.
Conducting experimental shootings from TT and PM pistols, N.B. Cherkavsky (1958) found that at shot distances from 5 to 25 cm, smokeless powder gases, in addition to carboxyhemoglobin, can also form methemoglobin, which must be remembered when determining the shot distance and brand of gunpowder. When this powder burns, nitrogen is formed, which in the air is oxidized into nitrogen oxide with the latter transforming into dioxide and nitric acid. The presence of nitrogenous compounds allows them to combine with hemoglobin in the blood and form methemoglobin.
Thermal effect of flame . The shot is accompanied by the formation of a flame. It occurs both in the lumen of the weapon's barrel, as a result of a flash of an explosive mixture and combustion of gunpowder (fire from the barrel), and outside it, near the muzzle (the muzzle flame is observed at some distance from the muzzle), as a result of the meeting of combustion products of gunpowder with oxygen.
The effect of the flame is determined by the rate of combustion of the gunpowder: the faster the combustion, the less the effect. The combustion time of the gunpowder is influenced by: the quantity and quality of the gunpowder, the nature of the explosive mixture, the speed of its flash, determined by the quality of the primer, the speed at which the striker acts on it and its shape, the length of the weapon barrel, the presence or absence of a muzzle brake, barrel defects (worn or shortened).
The size of the muzzle flame depends on the caliber of the weapon, the initial speed of the bullet, and the degree of gas pressure. Shots from a lubricated weapon reduce the magnitude of the muzzle flash.
For centuries, it was believed that the fall was caused by the direct action of flames caused by the combustion of gunpowder and emitted as a "tongue of fire" from the barrel of the weapon. In 1929, the French forensic physician Chavigny established that in gunshot injuries it is not the flame that acts, but the burning powder ejected from the barrel, the introduction of which begins to ignite the target object. Powder particles flying out of a revolver at close range and falling into cotton fabric ignite it at a distance of up to 1.5 m, reaching 1500-3000 ° C.
High gas temperature. Thermal effects can be caused not only by flame, but also by the high temperature of gases, powder grains, and their residues, soot particles formed as a result of combustion rania gunpowder Especially a lot of dense particles are produced by the combustion of black powder and a small amount of smokeless powder, which, when burned, leaves practically no solid residue. The observed abscission is usually caused by a flash of gases. Given the extreme short duration of the latter, the possibility of thermal action is determined by the gas pressure, which sometimes reaches enormous values near the muzzle. Scorching can be caused either by the direct impact of a shot, or by exposure to flames and high temperatures generated during the burning and smoldering of clothing. The scorching caused by the direct action of the shot is most pronounced on the hair if it is present in the area of the entrance hole.
Soot - a product of the combustion of gunpowder, producing smoke consisting of tiny, with an admixture of larger, soot-like particles suspended in powder gases containing mainly metal oxides (copper, lead, antimony) heated to a temperature of more than 1000 °. There is either no carbon in them, or there are only traces of it.
The flight range of soot is determined by the type of gunpowder and weapon.
Smokeless powder always contains various impurities - graphite, coal, diphenylamine, urea derivatives, barium salts and others, forming a solid residue that settles around the inlet. The soot of smokeless powder consists of black, sharply contoured round particles ranging in size from 1 to 20 microns, located depending on the distance of the shot at different depths in the skin and clothing.
The area of soot deposits and the accuracy of the introduction of powder particles have long been used to clarify the distance of a close shot. If there is soot and powder particles, then the distance is less than 15-30 cm; if there are powder particles, the distance is 15-100 cm. When assessing these data, it is necessary to proceed from a specific type of weapon.
Due to the peculiarities of the state of the disturbed air around the flying bullet, the soot flies and settles in an uneven layer. In its flying mass, two layers can be distinguished: the inner (central), more dense, and the outer, less dense. Therefore, around the wound, especially when shooting at close range, it is necessary to distinguish two belts - the inner, darker, and the outer, lighter. Often the outer layer of soot separates from the inner one, and a space is formed between them that is almost free of soot or contains it in small quantities. In this case, the settled soot separates the outer ring from the inner ring with a lighter intermediate ring. Sometimes there is no separation of the rings.
During the study it is necessary: to measure both rings - their radii and width, as well as the width of the light gap between the rings; describe color, density, external configuration. This is necessary to determine the distance of the shot and the properties of the weapon. The presence or absence of soot is determined by the distance of the shot and the design features of the weapon.
The shape of the soot is determined by the direction of the shot, but sometimes, with a perpendicular shot at close range, the soot is deflected to the side, which is explained by the tendency of the heated soot particles upward and the formation of a wider overlap on the upper side.
In some cases, the soot forms peculiar shapes that make it possible to judge the make and model of the weapon.
At the moment of a shot at a very close distance, soot may be reflected by the surface and fly back, which is observed on the hand of the suicide holding the weapon.
From a point-blank shot, a secondary soot field may arise (V.I. Prozorovsky, 1949), formed due to the displacement of the muzzle hole to the side at the moment of the shot, when the soot has not yet all come out of the barrel and, settling, forms a round figure near the entrance hole.
Soot deposits can be observed when fired from a short distance, when struck by ordinary bullets, or by special-purpose bullets with thermal activation.
The intensity and nature of soot deposits are determined by the distance and number of shots, target material, make and model of weapon, terms and conditions of ammunition storage.
powder
At the moment of the shot, not all powders ignite and not all ignited ones burn out. This depends on the weapon system, barrel length, type of gunpowder, shape of the powder, “old age of the gunpowder,” storage conditions, significant temperature fluctuations, high humidity, weakening of the primer due to partial decomposition of the primer composition.
Powder particles ejected from the bore fly to different distances depending on the type of gunpowder, the properties of the powder particles, the type of weapon, the shape and mass of the powder particles, the quantity and quality of gunpowder, the size of the charge, the conditions of its combustion, the distance of the shot and the properties of the obstacle, the design of the muzzle of the weapon, the mass particles of soot and powder, the ratio of barrel and projectile caliber, case material, number of shots, temperature and humidity environment, material and nature of the surface, density of the barrier.
Each powder can be considered as a separate small projectile with a large initial speed and a certain “living” force that allows it to cause certain mechanical damage and penetrate to some depth into the tissue or just stick to it. The larger and heavier each grain of powder, the further it flies and penetrates deeper. Coarse-grained powders fly further and penetrate deeper than fine-grained ones; cylindrical and cubic grains of smokeless powder fly further and penetrate deeper than lamellar or flake ones.
Flying out of the barrel, the powder particles fly after the bullet, dispersing in a cone-shaped manner, which is due to the large expenditure of energy to overcome the air environment. Depending on the distance of the shot, the distance between the particles and the radius of their dispersion become larger.
Sometimes the powder burns out completely, making it impossible to judge the distance of the shot.
Flying at low speeds, the powder particles settle on the skin; at higher speeds, they cause abrasions, occasionally surrounded by bruising; at very high speeds, they completely pierce the skin (Fig.142), forming a permanent tattoo of bluish dots. In living persons, after healing of injury sites with powders, brownish crusts form, which fall off along with the powders included in them, which must be removed to determine the shooting distance in cases of self-harm and self-mutilation. Powders penetrating to great depths cause an inflammatory reaction, expressed by redness and the formation of crusts at the sites of their penetration.
Flying powders and their particles, reaching the hair, split off thin plates from its surface, sometimes firmly embedded in the thickness of the hair and even interrupting it.
Temperature effect of powders . Black powder can singe hair, occasionally cause skin burns, and even ignite clothing.
Smokeless powder does not burn the skin and does not singe hair, which makes it possible to judge the type of gunpowder in cases where there is no powder.
Bullet
Moving along the bore rifled weapons, the bullet, rotating along the screw rifling, makes about one revolution around the longitudinal axis. A bullet rotating in the air in front of itself at the head end compresses the air, forming a head ballistic wave (compression wave). A rarefied bullet space and a vortex wake are formed at the bottom of the bullet. Interacting with the medium with its side surface, the bullet transfers part of its kinetic energy to it, and the boundary layer of the medium acquires a certain speed due to friction. Dust-like particles of metal and soot from a shot, following the bullet in the behind-the-bullet space, can be transported there at a distance of up to 1000 m and deposited around the entrance hole on clothing and the body. Such accumulation of soot is possible when the projectile speed exceeds 500 m/s, on the second lower layer of clothing or skin, and not on the first (top), as happens when shooting at close range. Unlike a shot at close range, the deposit of soot is less intense and has the shape of a radiant rim around the hole pierced by the bullet (Vinogradov’s sign).
Once in the body, the bullet forms a gunshot wound, which is distinguished: the zone of the immediate wound channel; zone of tissue bruise of the walls of the wound canal (from 3-4 mm to 1-2 cm), zone of comotion (tissue shaking) 4-5 cm wide or more.
The area of the immediate wound channel.When a bullet hits the body, it delivers a powerful blow in a very small area, compresses the tissue and partially knocks it out, throwing it forward. At the moment of impact, a shock head wave appears in the soft tissues, which rushes in the direction of the bullet at a speed significantly exceeding the speed of the bullet. Shock wave spreads not only in the direction of flight of the projectile, but also to the sides, as a result of which a pulsating cavity is formed several times larger than the volume of the bullet, moving after the bullet, which collapses and turns into a regular wound channel. In soft tissues, phenomena of environmental shaking (molecular shaking zone) occur, occurring after several hours and even days. In living individuals, tissues subjected to molecular shock become necrotic, and the wound heals by secondary intention. Pulsations of the cavity create phases of negative and positive pressure, facilitating the penetration of foreign bodies into the depths of the tissues.
The rapid collapse of the pulsating cavity in the initial part of the wound channel sometimes splashes out blood and damaged tissue in the opposite direction of the bullet's movement. When fired at point-blank range and at a shooting distance of 5-10 cm, drops of blood can get onto the weapon and even into the barrel.
The size of the temporary cavity is determined not only by the energy transferred by the bullet to the tissues, but also by the speed of its transmission, and therefore a bullet with a smaller mass traveling at a higher speed causes deeper damage. In the area adjacent to the wound channel, the head shock wave can cause significant destruction of the head or chest without damage to large vessels or vital organs from the bullet itself, as well as bone fractures.
The same bullet, depending on the speed of kinetic energy, the path traveled in the body, the state of organs, tissue density, and the presence of fluid in them, acts differently. Entry and exit are characterized by contusional, piercing and wedge-shaped action; exit - contusion and wedge-shaped; damage internal organs with the presence of liquid - hydrodynamic; bones, cartilage, soft tissues and skin of the opposite side - contusion.
Depending on the magnitude of kinetic energy, the following types of action of a bullet on the human body are distinguished.
Bullet penetrationoccurs when the kinetic energy is equal to several tens of kilograms. A bullet moving at a speed of over 230 m/s acts as a punch, knocking out tissue, as a result of which a hole of one shape or another is formed, determined by the angle of entry of the bullet. The knocked-out substance is carried away by the bullet over a considerable distance.
The entrance hole in the skin, when fired at an angle close to straight or 180°, and the bullet enters with the nose or bottom, has a rounded or irregularly rounded (due to tissue contraction) shape and dimensions, somewhat smaller than the diameter of the bullet. Entering the bullet sideways leaves a hole that matches the shape of the bullet's profile. If the bullet was deformed before entering the body, the shape of the hole will reflect the shape of the deformed bullet. The edges of such a hole are surrounded by uniform sedimentation, the walls of the wound are vertical.
The entry of a bullet at an acute angle leaves a settling on the side acute angle, on the same side, the bevel of the walls is also revealed, and the overhang is on the side of the obtuse angle.
Explosive action of a bullet observed when the kinetic energy is equal to several hundred kilograms. A powerful impact from a bullet, the force of which is concentrated on a small area, causes tissue compression, rupture, partial knockout and ejection, as well as compression of the tissue around the bullet. Following the passage of the bullet, part of the compressed tissue continues its movement to the sides, resulting in the formation of a cavity several times larger than the diameter of the bullet. The cavity pulsates and then collapses, turning into a regular wound channel. Morphologically, the explosive action of a bullet manifests itself in tearing and cracking of tissue over a larger area than the size of the bullet. This is due to the very large “living” force of the bullet, its hydrodynamic action, damage to the bullet casing, incorrect flight of the bullet, passage of bullets through human tissues of varying density, and damage by special bullets (eccentrics).
The explosive action of a bullet should not be confused with the action of explosive bullets, which contain an explosive substance that explodes when the bullet hits the body.
Wedge-shaped action possess bullets flying at speeds less than 150 m/s. The kinetic energy of a bullet is equal to several kilograms. Having reached the target, the bullet acts like a wedge: it compresses the soft tissues, stretching them, protruding them in the form of a cone, tearing them and, penetrating inside, depending on the amount of kinetic energy, to one depth or another, forming a blind wound. The shape of the entrance hole in the skin depends on the angle of entry of the bullet into the soft tissue; the deposition band will be larger compared to the penetrating effect of the bullet. This is explained by the lower speed at which the bullet enters the body. The bullet does not carry away soft tissues and bone fragments with it, which is due to the moving apart of the soft tissues and the collapse of the walls of the wound canal.
Impact or concussion effect of a bullet manifests itself in cases of loss of speed and kinetic energy by a bullet. At the end of the flight, the bullet can no longer cause the characteristic gunshot wounds and begins to act like a blunt object. The impact of a bullet on the skin leaves an abrasion, an abrasion surrounded by a bruise, a bruise, or a superficial wound. An impact with a nearby bone deforms the bullet.
Hydrodynamic action of a bullet is expressed in the transfer of bullet energy by a liquid medium around the circumference to the tissue of the damaged organ. This effect occurs when a bullet moving at very high speed enters a cavity with liquid contents (the heart filled with blood, the stomach and intestines filled with liquid contents) or tissue rich in liquid (brain, etc.), which leads to extensive destruction of the head with cracking of the skull bones, ejection of the brain, rupture of hollow organs.
Combined action of a bullet manifests itself in its sequential passage through several areas of the body.
Fragmentation and bullet action has a bullet that explodes near the body, producing numerous fragments that cause damage.
A bullet that hits a bone causes a variety of damage, depending on the amount of kinetic energy. Moving at high speed, it causes additional damage to soft tissues and organs, moving in the direction of its flight with bone fragments and fragmented fragments.
Shot factors (accompanying shot products - PPV (powder gases, shot soot, residues of powder grains, etc.), depending on a number of conditions, always cause entrance and sometimes exit wounds, called entrance and exit holes connected by a wound channel.
